XML 103 R89.htm IDEA: XBRL DOCUMENT v3.19.2
Fair Value Measurements - Additional Information (Detail) - USD ($)
$ in Millions
Jun. 30, 2019
Jun. 30, 2018
Level 3 [Member]    
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]    
Estimated fair value of long-term debt $ 192.7 $ 8.5